JPS6153761B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an audio repeat playback device, and an object of the present invention is to provide a device that repeatedly plays back a portion of an audio signal on a tape recorded with a general audio tape recorder without interruption. It is to provide.

BACKGROUND OF THE INVENTION Conventionally, when writing down oral texts, such as the contents of lectures and lectures, it has been conventionally recorded on a tape recorder and written by listening to the reproduced audio. but,
This method allows you to speak faster,
If the content is difficult to hear, the procedure is to manually stop playback at an appropriate point, rewind the tape to the required position, and start playback again. It is also necessary to repeat. In such cases, when rewinding to the required point, it is done manually and the cue cannot be found properly.In other words, rewinding too much may cause unnecessary parts to be played, or conversely, rewinding insufficiently and requiring further rewinding. In addition, when reproducing and rewinding is performed many times, the rewinding time (including the time required for cueing) is extremely wasted. There is a method of using a tape counter as a means of cueing, but this method does not solve the problem of saving rewinding time and has the disadvantage that it requires time and effort to set the tape counter each time. Another method is to record cue signals (index signals) at appropriate breaks in sentences, and when playing back, record the signal between those signals on another tape and play it repeatedly. In this case, a special audio tape that can record cue signals is A tape recorder is required, and if the cue signal is recorded when recording the content of the lecture, it becomes impossible to record the content of the lecture during that time, and the timing of recording the cue signal is also difficult, so this method is difficult to implement in practice. It becomes a problem.

The present invention solves the above-mentioned problems, and focuses on the fact that human speech has breaks in speech (speech) at relatively short time intervals. The main feature of the present invention is that, as shown in FIG. Equipped with a function to detect when the sound level is below a certain level for more than a certain period of time (hereinafter referred to as audio interruption), and an endless recording medium 36 (second recording medium) whose speed is variable over a certain range and capable of recording and reproducing. That's what I'm doing. The configuration will be described below with reference to the drawings as examples. The start command signal (Fig. 2a) turns on the playback operation drive circuit (hereinafter called PB drive circuit) 15 of the audio tape recorder (hereinafter called ATR) section 1, and the playback operation (hereinafter called PB) starts. and tape 2
The audio signal recorded on the (first recording medium) is reproduced by the reproduction head 3. Furthermore, the amplifier circuit 7
The reproduced audio signal (FIG. 2b) amplified by the detector circuit 8 undergoes envelope detection and is converted to a DC level (FIG. 2c), and is input to one input terminal 38 of the comparator circuit 9. Ru. The other input terminal 39 of the comparator circuit has a reference DC voltage Vref connected to the variable power supply 1.
Applied by 0. When the reproduced audio signal (Fig. 2b) is interrupted for a certain period of time and the output level of the detection circuit 8 becomes less than Vref, the output of the comparator circuit 9 is inverted, and this information is transferred to the gate circuit 11 (for a certain period of time _t3 , which will be described later). It is ON after the elapse of time - Fig. 2 e), through the OR circuit 12 and gate circuit 13 (as shown in Fig. 2 j, it is ON while ATR1 is operating).
The voltage is applied to the PB drive circuit 15 of ATR1 to stop the PB, and the rewind drive circuit 16 (hereinafter referred to as REW
This is called a drive circuit. ) is turned on and rewinding (hereinafter referred to as REW) is started. The time width of the interruption time of the playback audio signal that can be detected as described above is:
It is determined by the relationship between the time constant of the detection circuit 8 and the reference voltage Vref value. Therefore, by arbitrarily setting both values, the time width of the interruption can be arbitrarily determined.

Incidentally, a gear 5 of a frequency generator (FG) is attached and fixed to the reel stand main shaft 4 of the ATR 1 with the same central axis. As mentioned above,
ATR1 by the start command signal (Figure 2a)
Since the PB starts, the reel stand main shaft 4 naturally starts to rotate, and the gear 5 also rotates accordingly. As the gear 5 rotates, the teeth of the gear 5 cross the gap of the rotation detection head 6, thereby generating pulses in the output of the detection head 6. This pulse is the amplifier circuit 1
7 and a buffer circuit 18 to shape the waveform,
The pulses are input to the up/down counter circuit 20 which is reset by the start command signal (FIG. 2a), and the number of pulses is counted. This up/down counter circuit 20 is a flip-flop 2 (hereinafter referred to as FF2) which is set by a start command signal (FIG. 2a) and normally reset by the inverted output of the comparator circuit 9 upon detecting an interruption in the reproduced audio signal.
The up/down is controlled by the Q output (Fig. 2e) of ATR1, and up counting is performed during PB of ATR1, and down counting is performed during REW. By controlling the up/down counter circuit 20 in this way, its output starts from 0 and increases at the same time as PB of ATR1, and when PB stops, the output stops increasing at a certain value.
When REW occurs, the reel stand main shaft 4 rotates in the reverse direction, but of course a pulse is generated by the detection head 6, so the output value of the up/down counter circuit 20 decreases from that value, and the PB When the same number of pulses are generated in the detection head 6, its output value becomes zero. This state of returning to 0 is detected by the all-0 detection circuit 21, and flip-flop 1 (hereinafter referred to as FF1), which was set by the falling signal of the Q output of FF2 (Fig. 2 e), is reset ( Figure 2 j), REW of ATR1
The drive circuit 16 is turned off and REW stops (REW is stopped by setting the Q output of FF1).
has been started). In this way, the fact that the number of pulses from the detection head 6 during PB and REW is the same means that the number of rotations of the reel stand main shaft 4 during PB and REW are the same.
This means that the number of rotations is the same at the same time, so that the tape 2 is accurately cued to the playback start position by REW.

Next, the endless tape 36 runs at a predetermined speed until the operation of the endless recording medium (a second recording medium - hereinafter explained using the endless tape 36) becomes stable. is detected by the synchronization pull-in detection circuit 27), and PB of ATR1 is restarted after REW is completed. Here, in FIG. 2, the endless tape 36
The time required for the speed of ATR 1 to become stable after the end of REW is shown as t ₂ , but if the speed reaches a predetermined value and becomes stable during the REW operation of ATR 1, t ₂ =0.

At the same time as the second PB of the ATR 1 mentioned above, the reproduced audio signal (Fig. 2b) is transmitted to the recording amplifier 30,
The signal passes through a gate 31 and a head 35 and is recorded on an endless tape 36. Recording on this endless tape is performed at a tape speed of V at which the tape 36 goes around exactly in the same time as the PB time of the audio signal in ATR1.
It will be held in However, since the PB time t ₁ in the ATR 1 changes for each different series of audio reproductions, it is necessary to change the rotational speed of the motor 37 that drives the endless tape 36 each time. As shown in FIG.
It is set by a circuit system consisting of an A conversion circuit 25, a speed control circuit 26, and a motor drive circuit 28. By ANDing the Q output of FF2, which operates as described above, and the output of the clock pulse generator 29, the output of the AND gate 22 is FF2.
The number of pulses corresponding to the ON time of the Q output of ATR1, ie, the PB time t ₁ of ATR1 (FIG. 2), is generated (FIG. 2f). The number of clock pulses is counted by the counter circuit 23 which is reset by the start command signal (Fig. 2a), and its output is sent to the correction circuit 23.
4 to the D/A conversion circuit 25, and the D/A conversion circuit 25 converts the pulses according to the number of pulses.
The voltage is converted into a DC voltage (FIG. 3c) and input to the speed control circuit 26 which controls the rotational speed of the motor 37. Therefore, depending on this number of pulses, the PB of ATR1
The running speed of the endless tape 36 corresponding to time _t1 is set (FIG. 5). By the way, as mentioned earlier, in order to record the reproduced signal from the ATR 1 on the endless tape 36 for exactly one round, t ₁ =n/f=l/v...(1) [n: number of clock pulses (counter 23 (output value), : clock frequency, l: length of endless tape 36, v: running speed of endless tape]. By the way, D/A
As shown in Fig. 4, the output voltage V of the conversion circuit 25 and the rotational speed of the motor 37 (the running speed of the endless tape 36) are as follows: v=K ₁ V (2) (K ₁ : proportionality constant) There is a relationship, and if the digital output value of the correction circuit 24 is n', the relationship between n' and the output voltage of the D/A conversion circuit 25 is as shown in FIG. 3b: V=K ₂ n'... (3) (K ₂ is a constant of proportionality). If we find the relationship between n and n' from equations (1), (2), and (3), we get n'=(fl)/(K ₁ K ₂ n)...(4). Therefore, by correcting (converting) the output n of the counter circuit 23 in the correction circuit 24 as shown in equation (4), the endless tape 36 makes exactly one revolution in the playback time _t1 of the ATR1.

Next, the second audio reproduction of ATR 1 is stopped due to the detection of an interruption in the reproduced audio as described above, and ATR 1 waits at the beginning of the next audio signal. At this time, the recording to the endless soup 36 for exactly one round is stopped, and then the gate 33 is opened and the audio signal of the endless tape 36 is converted into the next start command signal by the reproducing amplifier 32 (which may also be used as the amplifier 7). (Figure 2 a) is played until it comes.

By the way, the PB time t of ATR1 is shown in Figure 5.
When t is very short like ₄ , the rotational speed of the motor 37 needs to be very high as can be seen from the figure, and this speed largely depends on the performance of the motor 37. The rotational speed of is close to ∞, which is impossible as a practical matter. For this reason, in this device, the gate circuit 1 is configured to ignore interruptions in the reproduced audio during _t3 after the start of the first reproduction of ATR1.
1 (Figure 2 l).

Conversely, if the playback time t of the ATR 1 is too long, the rotational speed of the motor 37 must be constantly slowed down, and at this time the endless tape 36 and head 35
When the relative speed with respect to the endless tape 36 decreases below a certain value, reproduction from the endless tape 36 becomes impossible. Therefore, the PB time t of ATR1 is a certain value t ₅
(Fig. 5) That is, when the output of the counter circuit 23 reaches its maximum value (all output bits are 1),
Detected by the all 1 detection circuit 19, this all 1
The output of the detection circuit 19 passes through the OR circuit 12,
Input to PB drive circuit 13 and FF2 and ATR1
PB stops. After that, the same operation as in the case of detecting an interruption in the reproduced audio described above is performed.

In the explanation of this device based on FIG. 1, an endless tape is used as an endless recording medium.
Any material that can record endlessly, such as a magnetic disk, magnetic sheet, or magnetic drum, may be used.

In Figure 1, as explained earlier, ATR1
The cue for REW was performed using the FG gear 5 and detection head 6 attached to the main shaft 4 of the reel stand of the ATR1, but in addition to that method, as shown in Fig. 6, there is a method used for the PBM of the ATR1. A detection circuit 4 that operates in parallel with the detection circuit 8 and comparison circuit 9 during REW.
5 and a comparison circuit 46 are provided, respectively.
It is also possible to adopt a configuration using SW1 that switches the output of the switch. This is intended to stop the operation during REW by detecting a break in the audio signal on tape 2, as in the case of PB. During the PB of ATR1, SW1, which had fallen to the contact 48, switches to the contact 49 during the REW, detects an interruption in the playback signal during the REW, and the information is passed through the output of the comparator 46 to the REW.
The signal is input to the drive circuit 16. The principle of detecting discontinuity in the reproduced signal during REW is the same as that for PB described above, however, since the reproduction frequency of the signal reproduced from tape 2 during REW is higher than that during PB, the time constant of the detection circuit 45 is It is set shorter than the detection circuit 8.

As described above, by using the apparatus of the present invention, the following effects can be obtained when transcribing oral texts, lyrics, etc. of lectures, lectures, etc. recorded on the tape 2.

1 The PB of ATR1 automatically stops by detecting an interruption in the reproduced audio signal after a certain period of time _t3 has elapsed since the start of playback of ATR1, or by detecting that a certain period of time _t5 has elapsed since the start of playback. There is no need to manually stop PB every time.

2. After the PB is stopped, rewinding of the ATR 1 and cueing to the playback start position are performed accurately and automatically, so the effort of rewinding and cueing can be saved compared to manual rewinding and cueing as in the past.

3. In rewinding ATR 1, the queue signal recorded on tape 2 is not used, so a tape recorded on an ordinary tape recorder can be used.

4 During the second PB in ATR1, the reproduced audio signal is recorded on the endless tape 36,
When it is desired to reproduce the same part again and again after the first time, it is reproduced from the endless tape 36, so there is no need to perform rewinding and cueing operations many times, which is very efficient. At this time, since tape 2 of ATR1 is waiting at the beginning of the next audio signal, it is possible to proceed to the next stage and perform PB of ATR1 immediately.

5 The playback time t in the ATR 1, that is, the time from a certain playback start point to the detection of an audio break (including the detection of a certain period of time elapsed), differs for each series of audio signals, but Since the tape is run at such a speed that it makes exactly one revolution in t each time it is recorded, the endless tape 3
There is no interruption at the beginning (head) and end of the reproduced audio from 6, making it very efficient to repeat the reproduction many times.

6. As shown in FIG. 5, the playback time t of the ATR 1 has a lower limit t ₂ and an upper limit t ₅ . The traveling speed is not extremely slowed down to make recording and reproducing impossible.

7 Normally, the audio signal recorded on the endless tape 36 is from the start of playback of the ATR 1 until the end of the playback audio signal, that is, until the break of a phrase, etc., so there is no break in the middle of a word in a sentence, and it is easy to write. The meaning of the words in the sentence will not become unclear.

8 The unit of the audio signal recorded on the endless tape is not based on control signals such as cue signals recorded on the tape, but audio interruptions are detected from the start of ATR1 playback (including detection of elapsed time). ), so it is possible to use a tape recorded with an ordinary tape recorder instead of a tape recorded with a special tape recorder.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing one embodiment of the present invention, Fig. 2 a to l are timing diagrams showing the operation of the device of the present invention, and Fig. 3 a to c are
A graph showing the relationship between the number of output pulses of the AND gate 22 and the output of the D/A conversion circuit 25, FIG. 4 is a graph showing the relationship between the input DC voltage and the rotation speed of the motor 29, and FIG. A graph showing the relationship between the playback time and the rotational speed of the motor 29, and FIG. 6 is a main circuit diagram showing another embodiment for cueing. 2...First recording medium, 3...Reproduction head, 4
... Reel stand main shaft, 5 ... Gear, 6 ... Rotation detection head, 36 ... Second recording medium.

Claims (1)

[Scope of Claims] 1. A period of time from the start of reproduction of an audio signal recorded on a first recording medium until it is detected that the level of the reproduced audio signal exceeds a certain time and is below a predetermined value; or a means for reproducing the audio signal A for a first time period which is shorter than a preset time from the start of the reproduction, and stopping the reproduction when the first time elapses; means for rewinding the audio signal A to a playback start position; and means for measuring and storing the playback time of the audio signal A;
an endless second drive which reproduces the audio signal A again for a time of
What is claimed is: 1. An audio repeat playback device for recording and playing back on a recording medium. 2. When the audio signal A obtained by reproducing the audio signal recorded on the first recording medium is recorded on the second recording medium, the reproducing means of the first recording medium is stopped, and the audio signal A is reproduced from the second recording medium. 2. An audio repeat playback device according to claim 1, wherein the audio signal A is repeatedly played back. 3 A pulse generating circuit whose number corresponds to the first time for reproducing the audio signal recorded on the first recording medium, a counting circuit which counts the number of pulses, and an inverse proportional calculation which inputs this counted value. 2. An audio repeat playback device according to claim 1, further comprising a circuit for performing arithmetic operation, and controlling the traveling speed of the second recording medium by the output of the arithmetic circuit. 4. A rotation detection gear is provided on the reel stand main shaft that holds the first recording medium, and a rotation detection head is provided near the rotation detection gear, so that as the reel stand main shaft rotates, the rotation detection gear is configured such that a pulse is generated when the recording medium crosses the rotation detection head, and when the audio signal recorded on the first recording medium is played back for a predetermined time and then rewound, the pulse generated during the rewinding. 2. The audio repeat playback device according to claim 1, wherein the rewinding is stopped when the number of pulses generated during playback is equal to the number of pulses generated during playback.